So today I got a CD-Rom unit from Samurai Ghost, system looked awesome. I took my region modded PC Engine and hooked it up, JP mode just crashed, but US mod was fine. It blew my mind, I knew the system worked fine by itself but on the CD unit it went bonkers. It has an older region mod chip (before electrochip's version) but essentially the same idea. I did some research and found this post:
Also when installing instead of using a 5V source, I have found that using the IN pin on the Voltage regulator is FAR more stable and you won't have issues where some games will crash after a few minutes of play.
I was about to replace the chip with one of the ones I previously got from Electrochip, when I just tried his suggestion, and gave the region chip more power. And guess what....it worked! I am beginning to think that those of you that have Neo Flash that don't work (and have region mod boards) might just need to swap to a stronger power source (like the input of 7805). Does anyone have issues with a non modded system and my theory is busted?